Incidence of some spore forming bacteria in market milk

Abstract

A total of one hundred raw milk samples collected from different localities of Damietta governorate (farmers, street vendors, supermarkets and, dairy shops). Storch’s test was performed for detection of heat treated milk samples that were 12, 8, 40 and, 16, respectively. Clostridium perfringens and Bacillus cereus were detected in 7 and 10% of examined raw milk samples. Alpha (cpa); enterotoxin (cpe) genes and hlbA; ces genes of isolated Clostridium perfringens and Bacillus cereus were characterized by PCR represented 85.7% (6); 0% and 60%(6); 20%(2) of each isolate, respectively. 20% of isolated B. cereus strains were not toxigenic according to the study, although all isolates were haemolytic. Growth, Lipolytic and Proteolytic activities of Bacillus cereus strains isolated from raw milk were studied at 30◦c and 7◦c in a percentage of 100, 40 and 20; 20,100 and 40, respectively. It was revealed from the previous results that 100% (10) of B. cereus isolates were mesophilic and 40% were phychrotophic. Potential health risk and economic importance of isolated strains were discussed.